Geochemical variations of the Pro terozoic
dolomite samples close to the ore deposits in the Renison
mine area, Tasmania, Austra lia. arc the result of alteration.
The oxygen tsotope va lues of the most altered dolomites
surrounding the orc deposit indicates that these arc affected
oy hot (up to abou t 350°C) hydro thermal nuids. There is a
trend of decreasing lighter oxygen and carbon isotope values
LOwards the are deposit. Carbon isotope val ucs in dolomites
are significantly lighter than those least· altered dolomites
away from mineralised area, due to alteration ranging from
47 to 95% . Oxygen isotope values arc also significantly
li ghter close 10 the a re deposil, than less allered sa mples
away from mineral ised area. Alteration in oxygen rang ing
from 20 10 97% . Geochemical analys is also indicates th aI
Fe a nd Mn are very high but Ca, Mg, Sr and Na arc very
low in dolomile sa mples close 10 Ihe ore deposils. Thus, the
result of thi s study shows Ih at the gradual decreases in
oxygen and carbon isotope values, which corresponds to the
increasing a lt e ralion perce nt , lowards Ihe o rebody, a long
with e lemenlal composi tio ns, are us eful for recognition of
ore deposiLs.